Pontoon, float, and the like



June 21, 1938. D, ROBERTS E M 2,121,052

PONTOON, FLOAT, AND THE LIKE Original Filed Jan. 15, I934 2 Sheets-Sheet 1 INVENTORS. Dudley Robe/'7;

Y Frear/cff W////dm Be/ ATTORNEY.

June 21, 1938. D. ROBERTS ET AL 2,121,052

PON'IOON, FLOAT, AND THE LIKE Original Filed Jan. 15, 1954 '2 Sheets-Sheet 2 INVENTORS v I Dudley Roberfs BY Freder/cA JAM/lam Ps'e/ ATTORNEY.

Patented June 21, 1938 UNITED STATES PATENT-LQFFICE 2,121,052 PONTOON, FLOAT, ANn'rnn Dudley Roberts, New York. N. Y., std-mafia William Peel, London, England, assignors to Q Rubat ex- Products, Inc., Wilmingtomj Del.,'-a' v comration'of Delaware o v Application January 15, ,1934, SerialNo.' 706,771

Renewed,November10,,1936

I H com n 1( Cl.' 114- -6 6.5) l I s Figure 10 is an end view of an army pontoon; v and v v a I Figure 11 is a side view of an army pontoon.

Our invention relatesto floating members suchas pontoons, life belts, buoys and the like.

I As is well known,.these members are made of light, durable material not readily aifected by water, and having little or no water-absorbing p p ty.

One simple means for producing 's'ufiicient displacement of water to obtain the overall specific gravity necessary to insure floating with applied loads is to inflate water-sealed members or to otherwise produce a water-sealed chamber.

In the case of hydroplane pontoons, it has .been the practice to construct a plurality of individual sections suitably sealed from each other to. preprovide a novel construction of pontoon.

A further object of our invention is to provide a pontoon for hydroplanes constructed. of our novel expanded rubber.

Still a further object of our invention is to pro-- vide novel life buoys constructed of our novel expanded rubber.

Still another object of our invention is to provide life belts and the like of our novel expanded rubber. I

There are other objects of our invention which together with the foregoing will appear in the detailed description to follow in connection with the drawings, in which: v

Figure 1 is a top view of one form of pontoon;

Figure 2 is a perspective side view of the pontoon shown in Figure 1;

Figure 3 is a view showing a side open to dis close the interior;

Figure 4 is a cross section of the pontoon shown in Figure 1 with our preferred expanded rubber suitably imbedded in the spaces of the pontoon;

Figure 5 is a perspective view of a life belt;

made of our preferred rubber product; I

Figure. 6 is a top plan view of a life boat buoyed by a structure made of our preferred rubber;

made in accordance with,

LIKE

We have discovered that these members, particularly pontoons, can be constructed of a specially prepared rubber which is durable, strong, cheap and is extremely buoyant, so that it can a considerable load fioating.-

This rubber, the novel process of manufacture of which will be described below, and which contains an inertgas under high pressure, is made with the following constituents:

support,

- Percent Washed first grade crepe or smoked rubber 40-75 Sulphur-. l 6-30 Light calcined magnesia 3- 5 Ground gilsonite a 12 Lower melting bituminous substances..- 12

In the manufacture of thisproduct, the crepe or smoked rubber is first masticated for a period of time depending on the poundage of rubber desired. To this is added an asphalt product such as bitumin,- uniformly distributed over the rub-' her. In order to fully impregnate the bitumen in the rubber, the mixture is taken to a dark room for a period of twenty-four hours rest, at

the. end of which time it is placed on a warm mill and heated to a'temperature not to exceed 100 degrees F. to plasticize the product.

With the product in a plastic state, the sulphur, calcined, magnesia and gilsonite, in proportion as stated above, are then added and the resultant mixture held inactive for a second rest period of twenty-four hours to permit thorough impregnation. The resulting dough is then taken and manufactured into 'various articles such as slabs, boards, etc. by means of a warm,- ing up mill or forcing machine, and then cut into desired sizes. I

These are then well chalked with French chalk and placed in acontainerfor gassing. The rubber containers are placed in an airtight warm gassing chamber or autoclave and the air pumped out from this chamber until a substantial vacuum is produced. All the oxygen in the rubber is thus withdrawn, preventing subsequent deterioration by the action of oxygen on the rubber.

This step is exceedingly important for a successful production of inflated rubber, as heretofore the failure to remove the oxygen has resulted in an early deterioration of the rubber.

Carbon dioxide, helium, nitrogen, or any noncombustible gas is then injected at a pressure complete expansion and vulcanization. This is accomplished as follows: 1 I

The pressure is increased when heat is applied by the admission of steam through a steamy jacket surrounding the gassing chamber forthe purpose of partially vulcanizing thesoft rubber containing the injected-gas. This steam Jacket,

which is a spiral perforated'tube, encircles the inner cylinder or gassing chamber to insure form distribution of heat. The steam pressure applied in the heating jackets may vary from four to sixteen pounds, and the heat is applied for a period of from two hundred to six hundred minutes, depending on the physical conditions of the rubber. product desired, such as the thickness of the material, weight, etc.- Only'partial vulcanization of the rubber has been accomp pushed up to this point.

The apparatus is now cooled either by permitbeing. preferred to save time.

siderable excess of .the gas admitted for. inflatber is removed from the gassing chamber.-

At. this time, as stated above, the rubber has been only partially vulcanized and has not yet been fully expanded to its maximum possibilities. Complete vulcanization and final expansion of this rubber material must be accomplished within twenty-four hours, in order to prevent loss of gas in the partly vulcanized rubber.

For the final vulcanization of the rubber, it is placedin a mold whose inner dimensions and shape are exactly the same as the external dimensions and shape of the desired article. This is then subjected to a further high temperature of heat, preferably steam, at from sixty to one hundred twenty pounds pressure, the time of ap plication varying, in accordance with the size of the molded material, anywhere from twenty-five minutes to twenty-three hours.

The end product of this process is a rubber which is spongy and inflated with a gas at high pressure and temperature until it expands and assumes a minute cellular structure, the cells of which are filled with the injected gas and a suitable preservative. A seal composition has been added which imprisons the occluded gases in the pores or cells or interstices after the pressure and heat have been removed.

The resulting product we have found has considerable strength and durability and yet is extremely light, its weight varying from two and one half to five pounds per cubic foot, depending upon the pressure and temperature treatment given as cited above and upon the cellular seal provided in a manner'which is now well known in the art.

In Figures 1 to 4, we have disclosed a pontoon to be used in conne'ction with airplanes. As shown in the cut-away portions of Figure 3, the

pontoon comprises the longitudinal sectionallif the art. "ting it to normally cool down, or by artificial means to cause more rapid cooling, theflatter...

} are considerably greater. ing the rubber, and this-excess is drawn fofi "slowly I and'stored in ether vats through a chalk sep- 'arator for subsequent use.

When the gas has all been withdrawn, the container with the rubmembers 2, having corrugations as shown at 4.

At the lower end of the member 3, flattened out as at 5, and secured by rivets or other suitable means to the duralumin, of which member 6 is composed. The upper portions of members 3 r are secured to each other by the channel-shaped at the stage described above, at which stage the rubber is molded and completely vulcanized.

Heat is applied and at the completion of the process, expanded rubber of our novel construction fills all of the spaces formed by the metal of the pontoon, as shown in Figure 4.

[It will be understood that the pontoon form structure shown in Figure 3 is placed in a mold to produce the shape of pontoon shown in Figure 4. Following the completion of the molding operation, a cat walk 8 is secured to the rubber in the channel I, as shown in Figure 4. Suitable fittingsare provided for securing the pontoon to the plane-in any desired manner well known in Thereare numerous advantages of this pontoon construction over that using separate waterm U sealed compartments. It is obviously less costly At this point the 'gas chamber contains econ-1 than the water-sealing. Its safety and durability A pontoon having a plurality ofwater-sealed compartments can be readily destroyed by the gunfire spray from a machine m t a p In thepresent structure, the destruction of the pontoon by gunfire is practically-impossible because of the infinite minute cellular structures of gun producing a leak in each compartthe expanded rubber. In addition, the lightness gives considerable buoyancy for carrying the load of the plane, and its durability and cheapness adds to its desirability for pontoon construction.

In Figure 5, we have disclosed a life belt comprising the fabric body portion I l with the straps l2 secured thereto and having secured thereto the expanded rubber molded into shape and to the fabric II in the manner described in detail hereinbefore. A buckle l5 secures the two fabric sections in any preferred manner.

In Figure 6 we have shown the invention applied to a life boat in'which a peripheral rim ll, made of our preferred rubber and molded into shape in the manner described in detail hereinbefore, has secured thereto in any desired manner, the net-like interior {8 of the boat. The advantages in simplicity, durability and floating power .of this construction should be obvious.

In Figure 8 we have disclosed nets 2|, suitably buoyed by buoy member .22 made of our preferred rubber. A pin 22 extending through the member 22' is bolted in place by nuts 24, from which depend connecting members 25 for securing the net 2| to member 22 of which there are any desired number.

In Figure 9 we have disclosed a signal buoy made of our rubber molded-in the desiredshape and having an opening extendin'gvthrougli it, through which extends 'abolt or pin 26 having rings 21 at each end. A chain'extending from the ring 21 connects the buoy to the anchor 28.

In carrying out our invention, we contemplate painting these buoys as well as mooring buoys, e rafts, belts and the like with a phosphorescent substance in order to make them luminescent at night.

In Figures 10 and 11, we have disclosed army pontoons comprising our novel rubber II and I2, molded as cylinders. A plate 33, preferably of metal, is molded in the rubber and carries a bolt 35 and 34 protruding from the molded rubber and extending through a plank II to which it'is suitably secured as by nuts it. Two such planks 31 are usually provided at the ends of the cylinders or rubber and carry boards II extending across from one to the other plank II to form a platform, as shown.

It will be obvious that these structures may be modified and are specifically disclosed merely for illustration. Accordingly, we do not wish to be limited except as set forth in the appended claims.

We claim:

20 1. A flotation member comprising a metal chamber and a hard and rigid closed cell rubber expanded therein to completely fill said chamber, said hard and rigid closed cell expanded rubber having a weight on the order of 2% to 5 pounds per cubic foot.

2. A flotation member comprising a metal chamber and a hard and rigid closed cell gas expanded rubber contained therein, said closed cell gas expanded rubber being expanded within said metal chamber. said hard and rigid closed cell gas expanded rubber having a weight on the order of 2% to 5 pounds per cubic foot.

3. A pontoon comprising a metal chamber and a hard and rigid closed cell rubber expanded therein to completely fill said chamber, said hard and rigid closed cell expanded rubber having a weight on the order of 2% to 5 pounds per cubic foot.

DUDLEY ROBERTS. 

